Complete self-contained multipurpose dairy processor unit for milk derivatives production

ABSTRACT

A complete self-containing multipurpose dairy processor unit in which a liquid is treated including a hot-water or steam generator and a heat exchanger immersible in the liquid to be treated and selectively feedable when immersed in the liquid being treated with hot water, steam or cold water depending on whether heat is to be transferred to the liquid to be treated or removed from the liquid to be treated, the hot water or steam being produced by the generator device. A generator including a turbine produces a flow within the liquid to be treated to cause the liquid to pass over the heat exchanger. The turbine is a variable-speed turbine which forces the liquid from a location below the heat exchanger upward into and through the heat exchanger.

FIELD OF THE INVENTION

This invention relates to a complete self-contained multipurpose dairyprocessor unit for milk derivatives production for bovine, buffalo,sheep and goat holdings and for public-access farms.

BACKGROUND OF THE INVENTION

Various types of plants for milk conversion in small quantity are known,constructed according to the classical scheme of the dairy farm andbased on a coagulation vessel, the walls of which have an interspacethrough which hot or cold water is circulated to achieve heat transferwith the milk or whey contained in it. These vessels are sometimesprovided with mechanical means for stirring and cutting the curd.

The use of this interspaced coagulation vessel usually requires twospecific hot or cold water feed systems which very often require aconsiderable time for accumulating the energy required for the process.They are always in the form of plants composed of piping, valving,connection fittings, hydraulic pumps and reservoirs requiring particularplant design and installation, with considerable cost and processingtime, as the milk to be processed, contained in the coagulation vessel,keeps the entire plant engaged until the end of the entire coagulationprocess. These plants are hence designed for specific milk quantitiesand are able to process only such specific milk quantities at a time.

OBJECTS AND SUMMARY OF THE INVENTION

U.S. Pat. No. 2,078,000 discloses an apparatus for thermal treatment ofliquids, particularly milk, comprising a heat exchanger device in theform of a coil which can be immersed in the liquid to be trated. Thecoil is selectively feedable with hot water, steam, or cold water,depending on whether heat is to be transferred to the liquid or removedfrom it. The coil has a vertical axis around which it can rotate inorder to improve the heat transmission. However, this apparatus isunsuitable for producing cheeses. In fact such a coil is unable forgenerating an effective flow in the liquid. Therefore, if the liquid tobe trated is a curd (in which lumps of casein are dispersed in a liquidphase) from which a cheese has to be obtained, the lumps of caseinadhere to the coil and degrades ("burn") thus compromising the wantedresult. Furthermore, within a short time the quantity of casein on thecoil also hinders the mechanical function of the coil which in practiceis no longer able to generate any flow.

An object of the present invention is to provide the user with acomplete self-contained multipurpose dairy processor unit for theproduction of milk derivatives, which allows the sequential processingof several milk quantities in several simple containers not forming partof the processor unit, with considerable utilization versatility and inany environment, while satisfying health regulations.

Further objects of the invention are:

from the technical viewpoint, to advantageously replace the many plantsand machines of the traditional cheese dairy, so achieving independencefrom the milk quantities to be processed;

from the technological viewpoint, to enable all the processes of anycheese dairy to be effected, to obtain all types of cheese both fromunpasteurized and from pasteurized milk, buttermilk curd, butter,yoghurt, etc.;

from the time viewpoint, to have available a processor unit which is ofimmediate use, which enables the coagulation time to be drasticallyreduced, and allows processing to be effected in sequence on severalmilk containers, which may be of different capacities.

A further object of the invention is to provide a dairy processor unitwhich is easy to clean, so offering maximum guarantee of hygiene andavoiding contamination of the liquid (milk or whey) to be treated, andis simple and economical to operate, without the use of specializedlabour or complicated technologies.

The invention hence consists of having concentrated in a singleprocessor unit all the heat transfer, physical-chemical, microbiologicaland mechanical functions currently performed in the various sectors andplants of a traditional cheese dairy, while satisfying healthregulations and without modifying the technology of traditional cheeses.

These and further objects which will be apparent hereinafter areattained by a dairy processor unit comprising:

a hot-water or steam generator device (14);

a heat exchanger device (18) immersible in the liquid to be treated andselectively feedable with hot water or steam produced by the hot-wateror steam generator device (14), or with cold water, depending on whetherheat is to be transferred to the liquid to be treated or removed fromit;

means to generate, within the liquid to be treated, a forced flow whichgrazes the heat exchanger (18);

characterized in that

the hot-water or steam generator device (14) is of the instantaneoustype; and

the means to generate within the liquid a forced flow is avariable-speed turbine which draws the liquid form the below and expelsit through the exchanger (18).

According to one embodiment of the present invention, mechanical meansfor stirring and cutting the curd can be connected to the flowgenerating means.

In this manner a complete self-contained multipurpose dairy processorunit is obtained. It should be noted that the term "cold water" meanswater the temperature of which is not substantially higher than ambient.Water having a temperature satisfying this requirement is for examplemains water, well water or spring water.

The hot water or steam generator is conveniently of the type usingliquid or gaseous fuel, and provided with operating and control meanspowered by the electric mains or by an electrical generator unit.

The lifting means can be operated either manually (in which case it isconveniently of the counterweighted type to limit operator fatigue), orby a pneumatic or hydraulic actuator, or by a geared motor unit poweredby the electric mains or by the said electrical generator unit. Theturbine for generating flow within the liquid to be treated can also beoperated by a geared motor powered in the same manner.

The various components of the processor unit according to the presentinvention can be mounted on one and the same support structure or base.

To allow the processor unit to be easily moved, the said structure canbe provided with wheels to allow it to be moved by pushing.

If the amount of movement required of the processor unit isconsiderable, it can be motorized for this purpose and provided with adriver's position, to finally assume the form of an actual motor vehiclewith an internal combustion engine.

According to a modified embodiment of the present invention, the heatexchanger device can consist of several heat exchangers, each providedwith a turbine. Such a modified embodiment can be useful if the mass ofliquid to be treated is considerable.

According to a further modified embodiment of the present invention, thelifting means can also consist of a monorail, possibly directionable,with a hoist from which the heat exchanger and relative turbine aresuspended.

The processor unit can also be provided with a conventional controldevice, for example of microprocessor type, to totally or partiallyautomate its operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will be moreapparent from the description of one embodiment thereof givenhereinafter with reference to the accompanying drawings, on which FIG. 1shows a very schematic side elevational view of the completeself-contained dairy processor unit according to the present invention.

FIG. 2 shows a schematic side elevational view of the completeself-contained dairy processor unit according to the invention includinga variable speed turbine (and wherein the same elements of FIG. 1 areprimed); FIG. 3 shows a view of the arm of the dairy processor unit inaccordance with the invention including a stirrer device (wherein thesame element of FIG. 1 is double primed); and FIG. 4 shows a view of thearm of the dairy processor unit in accordance with the inventionincluding curd cutting means (wherein the same element of FIG. 1 istriple primed).

DETAILED DESCRIPTION OF THE INVENTION

As can be seen from the figure, the processor unit 10 comprises a base12 carrying an instantaneous steam generator 14. The base also carries alifting means 16, from the rotatable arm 24 of which there is suspendeda heat exchanger 18, within the tube bundle of which there is coaxiallypositioned a variable speed turbine 35 (FIG. 2 and which includes vanes35a as is known in the art) which generates a flow within the liquid bydrawing liquid from below to then expel it laterally and radiallythrough the vertically extending tube bundle. A heat exchanger of thistype is for example described in Italian patent application No. MO93A000005 in the name of the present applicant and entitled a "RadialDynamic Heat Exchanger of Immersion Type".

Said turbine is supported by the heat exchanger 18 and is operated by ageared motor 22 positioned above the heat exchanger 18.

As can be seen from the figure, the lifting means 16 basically consistsof an upright 17, to the upper end of which there is hinged an arm 24operated by a cylinder-piston mechanism 19 via a suitable control unit30 (FIG. 2 and which includes vanes 35a as is known in the art) carriedby the base 12. It should however be noted that the lifting means canalso be operated in a different manner, for example hydraulically or bya geared motor, or even manually if provided with a counterweight tolimit operator fatigue. As already stated it can also be in the form ofa monorail, possibly directionable, with a relative lifting hoist.

As shown in the figure, the arm 24, and consequently the heat exchanger18, can assume two significant positions, namely a working or loweredposition in which the heat exchanger 18 is immersed in the liquid to betreated contained in the vessel 20 (this position shown in the figure byfull lines), and a raised position in which the heat exchanger 18 is outof the vessel (shown by dashed lines in the figure).

As can be seen from the figure, the shaft of the turbine (not visible)projects beyond the lower edge of the heat exchanger 18 and carriesfixed thereto a connection element 28 enabling the shaft to be connectedto a stirrer means 38 (FIG. 3) or a curd cutting means 40 (FIG. 4).

For simplicity, the figure does not show the hydraulic connections orthe electrical installation, or the valve enabling hot water or steam topass into the heat exchanger rather than cold water.

These are however obvious to an expert of the art.

As can be seen from the figure, the base 12 is provided with adjustablefeet 26. As stated, these can be replaced or supplemented at their sideswith wheels 34 (FIG. 2) to facilitate the movement of the processor unit10.

It should be noted that the vessel 20 normally does not form part of theprocessor unit 10, as it can be any vessel provided it is suitable forthe purpose and satisfies the health regulations applicable to theparticular case. In particular, it does not need to be a traditionalcopper vessel of interspaced type, with all the advantages which thisbrings.

The operation of the processor unit 10 will now be briefly described,although this should be apparent from the aforegoing. It will be assumedthat the heat exchanger 18 is already immersed in the liquid (milk orwhey) contained in the vessel 20 and that the turbine enclosed within itis in operation. As soon as the instantaneous hot water or steamgenerator 14 feeds hot water or steam into the heat exchanger 18 via therelative hydraulic circuit, the heat exchanger 18 begins to transferheat to the liquid in which it is immersed. This means that at theoutlet of the heat exchanger 18 there is condensate which is returned tothe instantaneous hot water or steam generator 14 to be retransformedinto hot water or steam, to hence repeat the cycle.

If instead the heat exchanger 18 is not immersed in the liquid and thesteam generator 14 is operated, the heat exchanger temperature tends torise to a value close to the temperature of the steam passing throughit, with the significant result of sterilizing and disinfecting it.

As already stated, the heat exchanger 18 can also operate in the reversedirection. In this respect it can be used to cool the liquid in which itis immersed merely by closing the steam feed and feeding it with coldwater, for example mains water (which normally has a temperature notexceeding 15° C.) or spring, well or similar water. Consequently theheat exchanger 18 then removes heat from the liquid in which it isimmersed, to cool it to the required temperature (which for theapplications of interest is substantially higher than mains watertemperature). The heat exchanger and the turbine enclosed within it, iethose parts of the processor unit 10 which come into contact with theliquid to be treated, are conveniently of stainless steel, this materialbeing preferred from the hygiene viewpoint. This eliminates one of theproblems of the traditional dairy industry, in which the vessel itself,necessarily of copper, has to be heated to transfer sufficient heat perunit of time to the liquid to enable the required result to be achieved.The result is that copper particles are transferred to the final dairyproduct (Japan has recently refused grain consignments because ofexcessive copper content under Japanese law). In our case, as the heatexchanger used results in a very high heat transfer rate, it is nolonger necessary to use copper for those parts transferring heat to thetreated liquid, so that the heat exchanger tubes can be constructed of amaterial of lower thermal conductivity than copper, such as stainlesssteel, hence overcoming the problem of copper particle release.

As will be apparent to the expert of the art, the described processorunit is of considerable versatility and achieves a very high heattransfer rate because of the presence of a radial dynamic heat exchangerof immersion type. This significantly reduces the time and cost of theproduction cycle without however changing the typicality of thetraditional manufacturing process. In addition the processor unitaccording to the invention enables any production requirement to besatisfied (from the individual shepherd level to the large industrialcheese dairy), with a truly significant energy saving over a traditionalplant.

This also results in a lesser environmental impact due to thesignificant reduction in burnt gas emission, complete elimination ofwater consumption for the coagulation, a considerable reduction indetergent effluent, and a significant reduction in the area required forproduction. Furthermore the processor unit of the invention enables thetraditional fixed-volume copper vessel of interspaced type to becompletely dispensed with, the vessel now being a simple vessel of anymaterial suitable for food use (such as stainless steel or food-suitableplastics).

I claim:
 1. A complete self-containing multipurpose dairy processor unitin which a liquid is treated, comprising:a generator for generatinghot-water or steam, a heat exchanger immersible in the liquid to betreated and selectively feedable when immersed in the liquid to betreated with hot water, steam or cold water depending on whether heat isto be transferred to the liquid to be treated or removed from the liquidto be treated, the hot water or steam being produced by said generator,and means for generating a forced flow within the liquid to be treatedto cause the liquid to pass through said heat exchanger, said generatingmeans comprising a variable-speed turbine operable at different speedsand arranged to force the liquid from a location below said heatexchanger upward into and through said heat exchanger.
 2. The processorunit of claim 1, wherein said generator is of the liquid or gaseous fueltype.
 3. The processor unit of claim 1, further comprising lifting meansfor lifting said heat exchanger from a first position in a container inwhich the liquid to be treated is placed to a second position out of thecontainer.
 4. The processor unit of claim 3, wherein said lifting meanscomprise a pneumatic or hydraulic actuator.
 5. The processor unit ofclaim 3, wherein said generating means further comprise an electricallypowered, geared motor suspended on said lifting means for rotating saidturbine at variable speeds.
 6. The processor unit of claim 1, furthercomprising a single support structure, said generator, said heatexchanger and said generating means being mounted on said supportstructure.
 7. The processor unit of claim 6, further comprising wheelsarranged on said support structure for enabling movement of said supportstructure.
 8. The processor unit of claim 1, further comprising acontrol device for totally or partially automating operation of theprocessor unit.
 9. The processor unit of claim 8, wherein said controldevice includes a microprocessor.
 10. The processor unit of claim 1,wherein said turbine includes a shaft which projects beyond a lower edgeof said heat exchanger, further comprising a connection element arrangedon said shaft for enabling said shaft to be connected to a stirrerdevice or a curd cutting device.
 11. The unit of claim 1, wherein saidheat exchanger comprises a tube bundle, said turbine being situated inan interior of said tube bundle such that the liquid is forced by saidturbine into the interior of said tube bundle and then laterally andradially outward between tubes of said tube bundle.
 12. The unit ofclaim 6, wherein the liquid to be treated is situated in a container,said support structure being completely separated from the container.13. A complete self-containing multipurpose dairy processor unit for theproduction of milk derivatives in which a liquid is treated,comprising:a generator device for generating hot-water or steam, a heatexchanger device immersible in the liquid to be treated and selectivelyfeedable when immersed in the liquid to be treated with hot water, steamor cold water depending on whether heat is to be transferred to theliquid to be treated or removed from the liquid to be treated, the hotwater or steam being produced by said generator device, means forgenerating a forced flow within the liquid to be treated to cause theliquid to pass through said heat exchanger, said generating meanscomprising a turbine arranged to force the liquid from a location belowsaid heat exchanger upward into and through said heat exchanger, asingle support structure, said steam generator, said heat exchanger andsaid generating means being mounted on said support structure, andwheels arranged on said support structure for enabling movement of saidsupport structure.
 14. The unit of claim 13, wherein said heat exchangercomprises a tube bundle, said turbine being situated in an interior ofsaid tube bundle such that the liquid is forced by said turbine into theinterior of said tube bundle and then laterally and radially outwardbetween tubes of said tube bundle.